Isolamento, caracterização e potencial biotecnológico de fungos endofíticos associados à plantas do cerrado

Abstract

Endophytic microorganisms are fungi or bacteria that colonize the interior of plant tissues without causing damage to the host plant. Endophytic fungi have interested the scientific community due to the production of secondary metabolites for application in the biotechnology and pharmaceutical industries. The present study aimed to isolate, purify, genotypically identify and evaluate the antagonistic activity, the biotechnological potential for phosphate solubilization and the enzyme production of 66 endophytic fungi from leaves and branches isolated from S. adstringens and S. lycocarpum St. Hill. For this, healthy leaves and stems of S. astringens and S. lycocarpum were collected and submitted to superficial asepsis. After the incubation of the botanical material, it was proceeded the isolation and molecular identification of the endophytic fungi. The endophytic isolates were evaluated in vitro for the antagonistic potential against phytopathogens Colletotrichum sp., Fusarium oxysporum and Lasiodiplodia subglobosa, for the solubilization of inorganic phosphate and the production of enzymes (amylase, cellulase, pectinase, protease, lipase and esterase). The results showed that the fungal endophytic community associated with S. adstringens is composed of: Diaporthe sp., Neopestalotiopsis sp., Nigrospora sp., Paraconiothrium sp., Phomopsis sp., Pseudofusicoccum sp., Schizophyllum sp. and Xenoacremonium sp. and the genera of the fungal community of S. lycocarpum St. Hill. is composed of: Colletotrichum sp., Curvalaria sp., Diaporthe sp., Neurospora sp., Phlebiopsis sp., Phomopsis sp. and Schizophyllum sp. Endophytic fungi have shown to be promising against Colletotrichum sp., Fusarium oxysporum and Lasiodiplodia subglobosa, with high inhibition rates and most type A interactions, where there is a block of phytopathogen growth with mycelial contact of the endophytic fungus . In addition, endophytic fungi had the potential to solubilize inorganic phosphate with a mean phosphate solubilization index. As for enzyme production, the fungal isolates of both plant species showed higher pectinolytic activity with pectate lyase production and polygalactorosis. Based on the results, the study evidences the importance of endophytic fungi in the production of compounds of interest for biotechnology and for the conservation of Cerrado plant species, which harbor these promising microorganisms.